Effect of Baby Walker Use on Developmental Status based on Ages and Stages Questionnaire Score (ASQ).

Objectives Baby walker is a popular device, which parents use for entertainment, keeping infants safe and walking promotion. We aimed to determine whether baby walker usage has any effect on the development using Ages and Stages Questionnaire (ASQ). Materials & Methods We evaluated 107 one-yr-old infants in each baby walker user group and non-users (214 participants) using ASQ test of 12-month in Isfahan health centers for vaccination in 2017. We re-evaluated 168 infants at the age of 18-month using ASQ test of 18-month. The data of these groups were compared. Results Girls use baby walker more frequently (P=0.02). Baby walker usage was not significantly associated with parent’s educational state, mother employment, birth rank of infant and delivery method. The starting age of baby walker use was 6.61 ± 1.46 months. ASQ results in area of gross movement and fine movement were not significantly different in users and non- users at age 12 and 18 months. Conclusion Most parents believe baby walker can promote earlier walking, but based on current evidence this belief might not be true. Although most studies showed no developmental delay in baby walker users, parents should become aware of their possible negative effects and hazards.


Introduction
Baby walker is a popular device on which a lot of money is spent annually (1). Baby walker usage reported 64%-92% in different population (2)(3)(4).
In Tehran, Iran, 54.5% of infants used baby walker and many parents believe that using baby walker helps their infants to walk earlier (5). In addition to possible negative effects on development, there are many concerns about baby walkerrelated injuries. About 12%-40% of baby walker users have experienced at least one related injury.
Because of these possible side effects and lack of evidence to support benefits of baby walker usage the American Academy of pediatrics recommends prohibition of the production and purchase of baby walkers (2).
The studies conducted to show whether baby walker use has significant effect on the development have led to conflicting results. Some studies reported no significant difference in gait acquisition between baby walker user and non-user infants (6)(7)(8); while others reported delayed motor development (9,10). Only one study showed significantly earlier walking skills in the user group (11). These studies are not reliable enough due to limitations including sample size, failure to randomize and absence of control group (12). Moreover, none of them used Ages and Stages Questionnaire (ASQ), which is one of the validated tests for evaluation of developmental status in Iran (13). Hence their results cannot be generalized to the Iranian population.
We aimed to determine the effect of baby walker on the developmental milestones in ASQ test on one-yr-old infants in Isfahan, central Iran.

Materials & Methods
This cross-sectional study was performed on oneyr-old infants referred to Isfahan health centers for vaccination in 2017. Three centers were selected by clustering method, 220 one-yr-old infants were entered in the study by easy sampling.

Results
Overall, 214 one-yr-old infants were enrolled.
Most infants (54%) were girls. Among parents, 56% of mothers and 49% of fathers had educational degree from diploma to bachelor. Overall 74.8% of mothers were unemployed ( The starting age of baby walker use was 6.61±1.46 months in the group of users. Among parents of baby walker users, 56% believed that baby walker helps infant to walk earlier, 33% were using baby walker to keep infants occupied and 11% were using baby walkers for other reasons. Among baby walker users, 2.8% and 1.2% of infants had abnormal result in ASQ in the area of gross movement in 12 and 18 months of age, respectively. This proportion was 0.9% and 1.1% in non-user group at 12 and 18 months of age respectively (Table 3).
In the area of fine movement, all the infants in user group had normal ASQ result although 0.93% of non-users had abnormal result at age 12 months (P=0.49). At the age of 18-month fine movement abnormality was found in 2.8% of the users but the entire group of non-users had normal result (P=0.11).

Discussion
According to our results, although gross movement abnormality was more frequent in baby walker users at age 12 month, no significant difference was found between the two groups in the area of gross movements at the age of 12 and 18 months Other similar studies performed have also led to conflicting results. In two study crawling and walking independently occurred significantly later in the baby walker user group (9,10). In a baby walker group, a significant delay was reported in the acquisition of all motor skills (14). Baby walker users also achieved lower scores in Bayley test compared with non-user group in Siegel study (9). On the other hand, despite the delayed onset of crawling in the baby walker user group, there was no significant difference in the onset of independent walking between the users and non-users (15). Four other studies also showed no difference on the age of gait acquisition between these two groups (5)(6)(7)(8). Contrarily baby walker user infants had earlier walking skills compared with non-users. Although the two groups had no significant difference in motor development using AIMS 1 (11).
There were some limitations in our study. We did not determine baby walker usage prevalence.
We could not collect any information about baby walker-related injuries due to time limitation and lack of reliable information in health care system.

Author`s contribution
OY participated in designing the study, scientific collection of information, analysis and interpretation of data.
MG participated in designing the study, scientific collection of information, drafting the paper, analysis and interpretation of data, Manuscript writing. SK participated in analysis, interpretation of data and cooperation in manuscript writing.
MS scientific collection of information.
All authors agreed to be accountable for all aspects of the work in ensuring that questions related to the accuracy or integrity of any part of the work are appropriately investigated and resolved.